Wright-Patterson Air Force Base

About: Wright-Patterson Air Force Base is a other organization based out in Wright-Patterson AFB, Ohio, United States. It is known for research contribution in the topics: Laser & Mach number. The organization has 5817 authors who have published 9157 publications receiving 292559 citations. The organization is also known as: Wright-Patterson AFB & FFO.

Self-compensation in semiconductors: the Zn-vacancy in Ga-doped ZnO

Abstract: Self-compensation, the tendency of a crystal to lower its energy by forming point defects to counter the effects of a dopant, is here quantitatively proven. Based on a new theoretical formalism and several different experimental techniques, we demonstrate that the addition of 1.4 \ifmmode\times\else\texttimes\fi{} 10${}^{21}$-cm${}^{\ensuremath{-}3}$ Ga donors in ZnO causes the lattice to form 1.7 \ifmmode\times\else\texttimes\fi{} 10${}^{20}$-cm${}^{\ensuremath{-}3}$ Zn-vacancy acceptors. The calculated ${V}_{\mathrm{Zn}}$ formation energy of 0.2 eV is consistent with predictions from density functional theory. Our formalism is of general validity and can be used to investigate self-compensation in any degenerate semiconductor material.

Quantitative Structure-Property Relationships for Melting Points and Densities of Ionic Liquids

Abstract: Although innumerable different ionic liquids are possible, even basic physical-property data, such as the density and melting point, exist only for relatively few. Derivation of melting point quantitative structure−property relationships (QSPRs) for energetic ionic liquids would therefore greatly aid in the molecular design of new compounds. A new class of ionic liquids, based on 1-substituted 4-amino-1,2,4-triazolium bromide and nitrate salts, were recently synthesized and their melting points and densities measured. We optimized the molecular geometries of the cations of the ionic liquids using ab initio quantum chemical methods. Melting point QSPRs were then derived from molecular orbital, thermodynamic, and electrostatic descriptors. Good correlations with the experimental data were found. The correlation coefficients for three-parameter melting point QSPRs and for one-parameter density QSPRs exceed 0.9. Although some of the descriptors that appear in our QSPRs were designed to describe chemical react...